Biochar Coated Seeds

ABSTRACT

The present invention provides for biochar coated particles and a method for coating the particles with biochar.

RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.16/780,629, titled BIOCHAR COATED SEEDS, filed on Feb. 3, 2020, whichapplication is a continuation of U.S. patent application Ser. No.15/184,325, titled BIOCHAR COATED SEEDS, filed Jun. 16, 2016 (now U.S.Pat. No. 10,550,044), which application claims priority to U.S.Provisional Patent Application Ser. No. 62/186,876 filed Jun. 30, 2015titled BIOCHAR COATED SEEDS and to U.S. Provisional Patent ApplicationSer. No. 62/180,525 filed Jun. 16, 2015 titled METHOD FOR APPLICATION OFBIOCHAR IN TURF GRASS ENVIRONMENT; U.S. patent application Ser. No.15/184,325 is also a continuation-in-part application of U.S. patentapplication Ser. No. 15/156,256 filed May 16, 2016 titled ENHANCEDBIOCHAR (now U.S. Pat. No. 9,809,502), which application claims priorityto U.S. Provisional Patent Application No. 62/162,219, filed on May 15,2015, titled Enhanced Biochar; U.S. patent application Ser. No.15/184,325 is also a continuation-in-part of U.S. patent applicationSer. No. 14/873,053 filed on Oct. 1, 2015, titled Biochars and Biochartreatment Processes (now U.S. Pat. No. 10,252,951), which claimspriority to U.S. Provisional Patent Application No. 62/058,445, filed onOct. 1, 2014, titled Methods, Materials and Applications for ControlledPorosity and Release Structures and Applications and U.S. ProvisionalPatent Application No. 62/058,472, filed on Oct. 1, 2014, titled HighAdditive Retention Biochars, Methods and Applications; U.S. patentapplication Ser. No. 15/184,325 is also a continuation-in-part of U.S.patent application Ser. No. 14/385,986 filed on May 29, 2012, titledMethod for Enhancing Soil Growth Using Bio-Char (now U.S. Pat. No.9,493,380), which is a 371 of PCT/US12/39862 filed on May 29, 2012,which is a continuation-in-part of U.S. patent application Ser. No.13/154,213 filed on Jun. 6, 2011 (now U.S. Pat. No. 8,317,891); and U.S.patent application Ser. No. 15/184,325 is also a continuation-in-part ofU.S. patent application Ser. No. 14/036,480, filed on Sep. 25, 2013,titled Method for Producing Negative Carbon Fuel (now U.S. Pat. No.9,359,268), which is a continuation of U.S. patent application Ser. No.13/189,709, filed on Jul. 25, 2011 (now U.S. Pat. No. 8,568,493), all ofthe above of which are incorporated in their entirety by reference inthis application.

BACKGROUND 1. Field of the Invention

The invention relates to plant seeds coated in biochar and to a methodof enhancing the efficacy of plant seed germination and establishment bycoating the seeds with biochar prior to planting.

2. Related Art

Biochar has been known for many years as a soil enhancer. Biochar iscreated by the pyrolysis of biomass, which generally involves heatingand/or burning of organic matter, in a reduced oxygen environment, at apredetermined rate. Such heating and/or burning is stopped when thematter reaches a charcoal like stage. The resulting biochar consists ofvarious pieces of residual solid material full of crevices, pores andholes that help store water, microorganisms and other nutrients thatpromote plant growth. The resulting pyrolyzed biomass will be referredto as “raw or untreated biochar.”

Raw biochar, while known for its soil enhancing characteristics, doesnot always benefit soil and, depending upon the biomass from which thebiochar is produced, could potentially be harmful to the soil, making itunsuitable for various types of crops or other productive uses. Inparticular, biochar can be detrimental, or even toxic, to 1) soilmicrobes involved in nutrient transport to the plant; 2) plants and 3)humans. Raw biochars derived from different biomass will have differentphysical and chemical properties and will behave quite differently. Forexample, raw biochar having pH levels too high, containing too much ashor inorganics, or containing toxins or heavy metal content too high canbe harmful and/or have minimal benefit to the soil and the plant life itsupports. Raw biochar can also contain unacceptable levels of residualorganic compounds such as acids, esters, ethers, ketones, alcohols,sugars, phenyls, alkanes, alkenes, phenols, polychlorinated biphenyls orpoly or mono aromatic hydrocarbons which are either toxic or notbeneficial to plant or animal life.

Currently, biochar has mostly been a scientific curiosity, not foundwide spread use, not found large scale commercial application, and hasbeen relegated to small niche applications. Due to a strong desire tocapture beneficial the soil enhancing characteristic of biochar, biocharresearch has continued in an attempt to harness biochar havingpredictable, controllable, and beneficial results as a soil amendment.Given the known benefits of biochar, a need remains for not only (i) amethod of producing biochar that can be used in large scale applicationsand having generally sustainable, controllable and/or particularphysical and chemical properties known to have the highest positiveimpact on soils, but also (ii) applications for biochar that benefit andenhance plant life and growth.

SUMMARY

The present invention relates to biochar coated seeds and a method forcoating seeds with biochar. Coating the seeds prior to planting candramatically reduce the need for high frequency saturation watering inthe period immediately following planting and can also increase plantgrowth and sustain plant life. The present invention can be used inconnection with any type of plant seed.

The present invention also includes a method for coating seeds with thebiochar. The method comprises the steps of (i) preparing a bindersolution by mixing a starch with deionized H₂O to create a solution;(ii) heating the binder solution to dissolve the starch; (iii) placingseeds in a rotary tumbler; (iv) dispensing the binder solution into thetumbler to coat seeds in a manner that lightly sprays the seeds withsolution; (v) tumbling the seeds until the seeds are evenly coated withthe binder solution; (vi) dispensing biochar in the tumbler to coat theseeds with biochar; and (vi) drying the coated seeds while tumbling.Optionally, a fertilizer, microbial inoculant, or other beneficial agentmay be added to also coat the seeds. Further, the steps of coating theseeds with the starch solution and dispensing the biochar may berepeated until the desired coating thickness is achieved.

Using biochar coated seeds increases the retention of water andnutrients around the seeds and surrounding soil, which enables superiorsoils rich in organic matter and microbial life. The use of biocharcoated seeds results in visibly fuller plants with improved vitality andlongevity that can be maintained with less water. Biochar, ideallytreated biochar, may also be used as a delivery mechanism or carrier forother items which are usually coated on seeds, such as nutrients,microbes, biological agents, or other substances with agriculturalefficacy. When prepared properly, biochar or treated biochar candemonstrate many advantages over other substrates used as carriers inseed coating applications, such as peat, calcined clay, or remnants ofagricultural products such as corn cobs.

Other devices, apparatus, systems, methods, features and advantages ofthe invention are or will become apparent to one with skill in the artupon examination of the following figures and detailed description. Itis intended that all such additional systems, methods, features andadvantages be included within this description, be within the scope ofthe invention, and be protected by the accompanying claims.

BRIEF DESCRIPTION OF THE FIGURES

The invention may be better understood by referring to the followingfigures. The components in the figures are not necessarily to scale,emphasis instead being placed upon illustrating the principles of theinvention.

FIG. 1 illustrates a cross-section of one example of a raw biocharparticle.

FIG. 2a is a SEM (10 KV×3.00K 10.0 μm) of pore morphology of treatedbiochar made from pine.

FIG. 2b is a SEM (10 KV×3.00K 10.0 μm) of pore morphology of treatedbiochar made from birch.

FIG. 2c is a SEM (10 KV×3.00K 10.0 μm) of pore morphology of treatedbiochar made from coconut shells.

FIG. 3 is a chart showing porosity distribution of various biochars.

FIG. 4 is a flow chart process diagram of one implementation of aprocess for treating the raw biochar in accordance with the invention.

FIG. 4a illustrates a schematic of one example of an implementation of abiochar treat processes that that includes washing, pH adjustment andmoisture adjustment.

FIG. 4b illustrates yet another example of an implementation of abiochar treatment processing that includes inoculation.

FIG. 5 is a schematic flow diagram of one example of a treatment systemfor use in accordance with the present invention.

FIG. 6 is a chart showing the water holding capacities of treatedbiochar as compared to raw biochar and sandy clay loam soil and ascompared to raw biochar and soilless potting soil.

FIG. 7 illustrates the different water retention capacities of rawbiochar versus treated biochar measured gravimetrically.

FIG. 8 is a chart showing the plant available water of raw biocharcompared to treated biochar (wet and dry).

FIG. 9 is a chart showing the weight loss of treated biochars verses rawbiochar samples when heated at varying temperatures using a TGA testingmethod.

FIG. 10 is a flow diagram showing one example of a method for infusingbiochar.

FIG. 11 illustrates the improved liquid content of biochar using vacuumimpregnation as against soaking the biochar in liquid.

FIG. 12a is a chart comparing total retained water of treated biocharafter soaking and after vacuum impregnation.

FIG. 12b is a chart comparing water on the surface, interstitially andin the pores of biochar after soaking and after vacuum impregnation.

FIG. 13 illustrates how the amount of water or other liquid in the poresof vacuum processed biochars can be increased varied based upon theapplied pressure.

FIG. 14 illustrates the effects of NPK impregnation of biochar onlettuce yield.

FIG. 15 is a chart showing nitrate release curves of treated biocharsinfused with nitrate fertilizer.

FIG. 16 is flow diagram of one example of a method for coating seedswith biochar.

FIG. 17 is an image of coated seeds of the present invention.

FIG. 18 illustrates one example of a cross-section of a coated particleof the present invention.

DETAILED DESCRIPTION

As illustrated in the attached figures, the present invention relates toboth seeds coated with biochar as well as a method for coating seedswith biochar that improves seed germination, increases survivability,and reduces water consumption by creating an area near the seed withincreased overall water holding capacity. It can also be used as amechanism to deliver microbes, nutrients, or other beneficial substancesto the soil or the germinating seed itself. As described below, rawbiochar may be treated to increase the water holding and retentioncapacities of the overall soil, or be infused with nutrients, microbes,or other beneficial substances or organisms. Through treatment, theproperties of the raw biochar can be modified to significantly increasethe biochar's ability to retain water and/or nutrients while also, inmany cases, creating an environment beneficial to microorganisms. Theprocessing of the biochar can also ensure that the pH of biochar used inthe present application is suitable for creating soil conditionsbeneficial for plant growth, which has been a challenge for rawbiochars. Treatment and inoculation techniques used during treatment canalso provide a biochar with much better properties as a microbial ornutritional carrier.

For purposes of this application, the term “biochar” shall be given itsbroadest possible meaning and shall include any solid materials obtainedfrom the pyrolysis, torrefaction, gasification or any other thermaland/or chemical conversion of a biomass, where the biochar contains atleast 55% carbon based upon weight. Pyrolysis is generally defined as athermochemical decomposition of organic material at elevatedtemperatures in the absence of, or with reduced levels of oxygen.

For purposes of this application, biochar may include, but not belimited to, BMF char disclosed and taught by U.S. Pat. No. 8,317,891,which is incorporated into this application by reference, and thosematerials falling within the IBI and AAPFCO definition of biochar. Whenthe biochar is referred to as “treated” or undergoes “treatment,” itshall mean raw, pyrolyzed biochar that has undergone additionalphysical, biological, and/or chemical processing.

As used herein, unless specified otherwise, the terms “carbonaceous”,“carbon based”, “carbon containing”, and similar such terms are to begiven their broadest possible meaning, and would include materialscontaining carbon in various states, crystallinities, forms andcompounds.

As used herein, unless stated otherwise, room temperature is 25° C. And,standard temperature and pressure is 25° C. and 1 atmosphere. Unlessstated otherwise, generally, the term “about” is meant to encompass avariance or range of ±10%, the experimental or instrument errorassociated with obtaining the stated value, and preferably the larger ofthese.

A. Biochars

Typically, biochars include porous carbonaceous materials, such ascharcoal, that are used as soil amendments or other suitableapplications. Biochar most commonly is created by pyrolysis of abiomass. In addition to the benefits to plant growth, yield and quality,etc.; biochar provides the benefit of reducing carbon dioxide (CO₂) inthe atmosphere by serving as a method of carbon sequestration. Thus,biochar has the potential to help mitigate climate change, via carbonsequestration. However, to accomplish this important, yet ancillarybenefit, to any meaningful extent, the use of biochar in agriculturalapplications must become widely accepted, e.g., ubiquitous.Unfortunately, because of the prior failings in the biochar arts, thishas not occurred. It is believed that with the solutions of the presentinvention may this level of use of biochar be achieved; and moreimportantly, yet heretofore unobtainable, realize the benefit ofsignificant carbon sequestration.

In general, one advantage of putting biochar in soil includes long termcarbon sequestration. It is theorized that as worldwide carbon dioxideemissions continue to mount, benefits may be obtained by, controlling,mitigating and reducing the amount of carbon dioxide in the atmosphereand the oceans. It is further theorized that increased carbon dioxideemissions are associated with the increasing industrial development ofdeveloping nations, and are also associated with the increase in theworld's population. In addition to requiring more energy, the increasingworld population will require more food. Thus, rising carbon dioxideemissions can be viewed as linked to the increasing use of naturalresources by an ever increasing global population. As some suggest, thislarger population brings with it further demands on food productionrequirements. Biochar uniquely addresses both of these issues byproviding an effective carbon sink, e.g., carbon sequestration agent, aswell as, an agent for improving and increasing agricultural output. Inparticular, biochar is unique in its ability to increase agriculturalproduction, without increasing carbon dioxide emission, and preferablyreducing the amount of carbon dioxide in the atmosphere. However, asdiscussed above, this unique ability of biochar has not been realized,or seen, because of the inherent problems and failings of prior biocharsincluding, for example, high pH, phytotoxicity due to high metalscontent and/or residual organics, and dramatic product inconsistencies.

Biochar can be made from basically any source of carbon, for example,from hydrocarbons (e.g., petroleum based materials, coal, lignite, peat)and from a biomass (e.g., woods, hardwoods, softwoods, waste paper,coconut shell, manure, chaff, food waste, etc.). Combinations andvariations of these starting materials, and various and differentmembers of each group of starting materials can be, and are, used. Thus,the large number of vastly different starting materials leads tobiochars having different properties.

Many different pyrolysis or carbonization processes can be, and are usedto create biochars. In general, these processes involve heating thestarting material under positive pressure, reduced pressure, vacuum,inert atmosphere, or flowing inert atmosphere, through one or moreheating cycles where the temperature of the material is generallybrought above about 400° C., and can range from about 300° C. to about900° C. The percentage of residual carbon formed and several otherinitial properties are strong functions of the temperature and timehistory of the heating cycles. In general, the faster the heating rateand the higher the final temperature the lower the char yield.Conversely, in general, the slower the heating rate or the lower thefinal temperature the greater the char yield. The higher finaltemperatures also lead to modifying the char properties by changing theinorganic mineral matter compositions, which in turn, modify the charproperties. Ramp, or heating rates, hold times, cooling profiles,pressures, flow rates, and type of atmosphere can all be controlled, andtypically are different from one biochar supplier to the next. Thesedifferences potentially lead to a biochar having different properties,further framing the substantial nature of one of the problems that thepresent inventions address and solve. Generally, in carbonization mostof the non-carbon elements, hydrogen and oxygen are first removed ingaseous form by the pyrolytic decomposition of the starting materials,e.g., the biomass. The free carbon atoms group or arrange intocrystallographic formations known as elementary graphite crystallites.Typically, at this point the mutual arrangement of the crystallite isirregular, so that free interstices exist between them. Thus, pyrolysisinvolves thermal decomposition of carbonaceous material, e.g., thebiomass, eliminating non-carbon species, and producing a fixed carbonstructure.

As noted above, raw or untreated biochar is generally produced bysubjecting biomass to either a uniform or varying pyrolysis temperature(e.g., 300° C. to 550° C. to 750° C. or more) for a prescribed period oftime in a reduced oxygen environment. This process may either occurquickly, with high reactor temperature and short residence times, slowlywith lower reactor temperatures and longer residence times, or anywherein between. To achieve better results, the biomass from which the charis obtained may be first stripped of debris, such as bark, leaves andsmall branches, although this is not necessary. The biomass may furtherinclude feedstock to help adjust the pH, cationic and anionic exchangecapacity, hydrophilicity, and particle size distribution in theresulting raw biochar. In some applications, it is desirous to havebiomass that is fresh, less than six months old, and with an ash contentof less than 3%. Further, by using biochar derived from differentbiomass, e.g., pine, oak, hickory, birch and coconut shells fromdifferent regions, and understanding the starting properties of the rawbiochar, the treatment methods can be tailored to ultimately yield atreated biochar with predetermined, predictable physical and chemicalproperties. Additionally, the biomass may be treated with variousorganic or inorganic substances prior to pyrolysis to impact thereactivity of the material during pyrolysis and/or to potentially befixed in place and available for reaction with various substances duringthe treatment process after pyrolysis. Trace materials, usually ingaseous form, but potentially in other forms, may also be injectedduring the pyrolysis process with the intention of either modifying thecharacteristics of the raw biochar produced, or for potential situationon the raw biochar so that those materials, or a descendant materialcreated by thermal or chemical reaction during pyrolysis, may be reactedwith other compounds during the treatment process.

In general, biochar particles can have a very wide variety of particlesizes and distributions, usually reflecting the sizes occurring in theinput biomass. Additionally, biochar can be ground, sieved, strained, orcrushed after pyrolysis to further modify the particle sizes. Typically,for agricultural uses, biochars with consistent, predictable particlesizes are more desirable. By way of example, the biochar particles canhave particle sizes as shown or measured in Table 1 below. Whenreferring to a batch having % inch particles, the batch would haveparticles that will pass through a 3 mesh sieve, but will not passthrough (i.e., are caught by or sit atop) a 4 mesh sieve.

TABLE 1 U.S. Mesh Microns Millimeters (i.e., mesh) Inches (μm) (mm)  30.2650 6730 6.370  4 0.1870 4760 4.760  5 0.1570 4000 4.000  6 0.13203360 3.360  7 0.1110 2830 2.830  8 0.0937 2380 2.380  10 0.0787 20002.000  12 0.0661 1680 1.680  14 0.0555 1410 1.410  16 0.0469 1190 1.190 18 0.0394 1000 1.000  20 0.0331  841 0.841  25 0.0280  707 0.707  300.0232  595 0.595  35 0.0197  500 0.500  40 0.0165  400 0.400  45 0.0138 354 0.354  50 0.0117  297 0.297  60 0.0098  250 0.250  70 0.0083  2100.210  80 0.0070  177 0.177 100 0.0059  149 0.149 120 0.0049  125 0.125140 0.0041  105 0.105 170 0.0035  88 0.088 200 0.0029  74 0.074 2300.0024  63 0.063 270 0.0021  53 0.053 325 0.0017  44 0.044 400 0.0015 37 0.037

For most basic agricultural applications, it is desirable to use biocharparticles having particle sizes from about 3/4 mesh to about 60/70 mesh,about 4/5 mesh to about 20/25 mesh, or about 4/5 mesh to about 30/35mesh. However, for applications such as seed treatment, or microbialcarriers, smaller mesh sizes ranging from 200, to 270, to 325, to 400mesh or beyond may be desirable. It is understood that the desired meshsize, and mesh size distribution can vary depending upon a particularapplication for which the biochar is intended.

FIG. 1 illustrates a cross-section of one example of a raw biocharparticle. As illustrated in FIG. 1, a biochar particle 100 is a porousstructure that has an outer surface 100 a and a pore structure 101formed within the biochar particle 100. As used herein, unless specifiedotherwise, the terms “porosity”, “porous”, “porous structure”, and“porous morphology” and similar such terms are to be given theirbroadest possible meaning, and would include materials having openpores, closed pores, and combinations of open and closed pores, andwould also include macropores, mesopores, and micropores andcombinations, variations and continuums of these morphologies. Unlessspecified otherwise, the term “pore volume” is the total volume occupiedby the pores in a particle or collection of particles; the term“inter-particle void volume” is the volume that exists between acollection of particle; the term “solid volume or volume of solid means”is the volume occupied by the solid material and does not include anyfree volume that may be associated with the pore or inter-particle voidvolumes; and the term “bulk volume” is the apparent volume of thematerial including the particle volume, the inter-particle void volume,and the internal pore volume.

The pore structure 101 forms an opening 121 in the outer surface 100 aof the biochar particle 100. The pore structure 101 has a macropore 102,which has a macropore surface 102 a, and which surface 102 a has anarea, i.e., the macropore surface area. (In this diagram only a singlemicropore is shown. If multiple micropores are present than the sum oftheir surface areas would equal the total macropore surface area for thebiochar particle.) From the macropore 102, several mesopores 105, 106,107, 108 and 109 are present, each having its respective surfaces 105 a,106 a, 107 a, 108 a and 109 a. Thus, each mesopore has its respectivesurface area; and the sum of all mesopore surface areas would be thetotal mesopore surface area for the particle. From the mesopores, e.g.,107, there are several micropores 110, 111, 112, 113, 114, 115, 116,117, 118, 119 and 120, each having its respective surfaces 110 a, 111 a,112 a, 113 a, 114 a, 115 a, 116 a, 117 a, 118 a, 119 a and 120 a. Thus,each micropore has its respective surface area and the sum of allmicropore surface areas would be the total micropore surface area forthe particle. The sum of the macropore surface area, the mesoporesurface area and the micropore surface area would be the total poresurface area for the particle.

Macropores are typically defined as pores having a diameter greater than300 nm, mesopores are typically defined as diameter from about 1-300 nm,and micropores are typically defined as diameter of less than about 1nm, and combinations, variations and continuums of these morphologies.The macropores each have a macropore volume, and the sum of thesevolumes would be the total macropore volume. The mesopores each have amesopore volume, and the sum of these volumes would be the totalmesopore volume. The micropores each have a micropore volume, and thesum of these volumes would be the total micropore volume. The sum of themacropore volume, the mesopore volume and the micropore volume would bethe total pore volume for the particle.

Additionally, the total pore surface area, volume, mesopore volume,etc., for a batch of biochar would be the actual, estimated, andpreferably calculated sum of all of the individual properties for eachbiochar particle in the batch.

It should be understood that the pore morphology in a biochar particlemay have several of the pore structures shown, it may have mesoporesopening to the particle surface, it may have micropores opening toparticle surface, it may have micropores opening to macropore surfaces,or other combinations or variations of interrelationship and structurebetween the pores. It should further be understood that the poremorphology may be a continuum, where moving inwardly along the pore fromthe surface of the particle, the pore transitions, e.g., its diameterbecomes smaller, from a macropore, to a mesopore, to a micropore, e.g.,macropore 102 to mesopore 109 to micropore 114.

In general, most biochars have porosities that can range from 0.2cm³/cm³ to about 0.8 cm³/cm³ and more preferably about 0.2 cm³/cm³ toabout 0.5 cm³/cm³. (Unless stated otherwise, porosity is provided as theratio of the total pore volumes (the sum of the micro+meso+macro porevolumes) to the solid volume of the biochar. Porosity of the biocharparticles can be determined, or measured, by measuring the micro-,meso-, and macro pore volumes, the bulk volume, and the inter particlevolumes to determine the solid volume by difference. The porosity isthen calculated from the total pore volume and the solid volume.

As noted above, the use of different biomass potentially leads tobiochars having different properties, including, but not limited todifferent pore structures. By way of example, FIGS. 2A, 2B and 2Cillustrate Scanning Electron Microscope (“SEM”) images of various typesof treated biochars showing the different nature of their poremorphology. FIG. 2A is biochar derived from pine. FIG. 2B is biocharderived from birch. FIG. 2C is biochar derived from coconut shells.

The surface area and pore volume for each type of pore, e.g., macro-,meso- and micro- can be determined by direct measurement using CO₂adsorption for micro-, N₂ adsorption for meso- and macro pores andstandard analytical surface area analyzers and methods, for example,particle analyzers such as Micrometrics instruments for meso- and micropores and impregnation capacity for macro pore volume. Mercuryporosimetry, which measures the macroporosity by applying pressure to asample immersed in mercury at a pressure calibrated for the minimum porediameter to be measured, may also be used to measure pore volume.

The total micropore volume can be from about 2% to about 25% of thetotal pore volume. The total mesopore volume can be from about 4% toabout 35% of the total pore volume. The total macropore volume can befrom about 40% to about 95% of the total pore volume. By way of example,FIG. 3 shows a bar chart setting out examples of the pore volumes forsample biochars made from peach pits 201, juniper wood 202, a first hardwood 203, a second hard wood 204, fir and pine waste wood 205, a firstpine 206, a second pine 207, birch 208 and coconut shells 209.

As explained further below, treatment can increase usable pore volumesand, among other things, remove obstructions in the pores, which leadsto increased retention properties and promotes further performancecharacteristics of the biochar. Knowing the properties of the startingraw biochar, one can treat the biochar to produce controlled,predictable and optimal resulting physical and chemical properties.

B. Treatment

The rationale for treating the biochar after pyrolysis is that given thelarge internal pore volume and large interior surface are of thebiochars, it is most efficient to make significant changes in thephysical and chemical properties of the biochar by treating both theinternal and external surfaces and internal pore volume of the char.Testing has demonstrated that if the biochar is treated, at leastpartially, in a manner that causes the forced infusion and/or diffusionof liquids and/or vapors into and/or out of the biochar pores (throughmechanical, physical, or chemical means), certain properties of thebiochar can be altered or improved over and above simply contactingthese liquids with the biochar. By knowing the properties of the rawbiochar and the optimal desired properties of the treated biochar, theraw biochar can then be treated in a manner that results in the treatedbiochar having controlled optimized properties.

For purposes of this application, treating and/or washing the biochar inaccordance with the present invention involves more than simplycontacting, washing or soaking, which generally only impacts theexterior surfaces and a small percentage of the interior surface area.“Washing” or “treating” in accordance with the present invention, and asused below, involves treatment of the biochar in a manner that causesthe forced, accelerated or assisted infusion and/or diffusion ofliquids, vapors, and/or additivities into and/or out of the biocharpores (through mechanical, physical, biological, or chemical means) suchthat certain properties of the biochar can be altered or improved overand above simply contacting these liquids with the biochar or so thattreatment becomes more efficient or rapid from a time standpoint oversimple contact or immersion.

In particular, effective treatment processes can mitigate deleteriouspore surface properties, remove undesirable substances from poresurfaces or volume, and impact anywhere from between 10% to 99% or moreof pore surface area of a biochar particle. By modifying the usable poresurfaces through treatment and removing deleterious substances from thepore volume, the treated biochars can exhibit a greater capacity toretain water and/or other nutrients as well as being more suitablehabitats for some forms of microbial life. Through the use of treatedbiochars, agricultural applications can realize increased moisturecontrol, increased nutrient retention, reduced water usage, reducedwater requirements, reduced runoff or leaching, increased nutrientefficiency, reduced nutrient usage, increased yields, increased yieldswith lower water requirements and/or nutrient requirements, increases inbeneficial microbial life, improved performance and/or shelf life forinoculated bacteria, increased efficacy as a substrate for microbialgrowth or fermentation, and any combination and variation of these andother benefits.

Treatment further allows the biochar to be modified to possess certainknown properties that enhance the benefits received from the use ofbiochar. While the selection of feedstock, raw biochar and/or pyrolysisconditions under which the biochar was manufactured can make treatmentprocesses less cumbersome, more efficient and further controlled,treatment processes can be utilized that provide for the biochar to havedesired and generally sustainable resulting properties regardless of thebiochar source or pyrolysis conditions. As explained further below,treatment can (i) repurpose problematic biochars, (ii) handle changingbiochar material sources, e.g., seasonal and regional changes in thesource of biomass, (iii) provide for custom features and functions ofbiochar for particular soils, regions or agricultural purposes; (iv)increase the retention properties of biochar, (v) provide for largevolumes of biochar having desired and predictable properties, (vi)provide for biochar having custom properties, (vii) handle differencesin biochar caused by variations in pyrolysis conditions or manufacturingof the “raw” biochar; and (viii) address the majority, if not all, ofthe problems that have, prior to the present invention, stifled thelarge scale adoption and use of biochars.

Treatment can impact both the interior and exterior pore surfaces,remove harmful chemicals, introduce beneficial substances, and altercertain properties of the biochar and the pore surfaces and volumes.This is in stark contrast to simple washing, contact, or immersion whichgenerally only impacts the exterior surfaces and a small percentage ofthe interior surface area. Treatment can further be used to coatsubstantially all of the biochar pore surfaces with a surface modifyingagent or impregnate the pore volume with additives or treatment toprovide a predetermined feature to the biochar, e.g., surface charge andcharge density, surface species and distribution, targeted nutrientaddition, magnetic modifications, root growth facilitator, and waterabsorptivity and water retention properties. Just as importantly,treatment can also be used to remove undesirable substances from thebiochar, such as dioxins or other toxins either through physical removalor through chemical reactions causing neutralization.

FIG. 4 is a schematic flow diagram of one example treatment process 400for use in accordance with the present invention. As illustrated, thetreatment process 400 starts with raw biochar 402 that may be subjectedto one or more reactors or treatment processes prior to bagging 420 thetreated biochar for resale. For example, 404 represents reactor 1, whichmay be used to treat the biochar. The treatment may be a simple waterwash or may be an acid wash used for the purpose of altering the pH ofthe raw biochar particles 402. The treatment may also contain asurfactant or detergent to aid the penetration of the treatment solutioninto the pores of the biochar. The treatment may optionally be heated,cooled, or may be used at ambient temperature or any combination of thethree. For some applications, depending upon the properties of the rawbiochar, a water and/or acid/alkaline wash 404 (the latter for pHadjustment) may be the only necessary treatment prior to bagging thebiochar 420. If, however, the moisture content of the biochar needs tobe adjusted, the treated biochar may then be put into a second reactor406 for purposes of reducing the moisture content in the washed biochar.From there, the treated and moisture adjusted biochar may be bagged 420.

Again, depending upon the starting characteristics of the raw biocharand the intended application for the resale product, further processingmay still be needed or desired. In this case, the treated moistureadjusted biochar may then be passed to a third reactor 408 forinoculation, which may include the impregnation of biochar withbeneficial additives, such as nutrients, bacteria, microbes, fertilizersor other additives. Thereafter, the inoculated biochar may be bagged420, or may be yet further processed, for example, in a fourth reactor410 to have further moisture removed from or added to the biochar.Further moisture adjustment may be accomplished by placing theinoculated biochar in a fourth moisture adjustment reactor 410 orcirculating the biochar back to a previous moisture adjustment reactor(e.g. reactor 406). Those skilled in the art will recognize that theordering in which the raw biochar is processed and certain processes maybe left out, depending on the properties of the starting raw biochar andthe desired application for the biochar. For example, the treatment andinoculation processes may be performed without the moisture adjustmentstep, inoculation processes may also be performed with or without anytreatment, pH adjustment or any moisture adjustment. All the processesmay be completed alone or in the conjunction with one or more of theothers. It should also be noted that microbes themselves may be part ofthe process, not simply as an inoculant, but as an agent to conveymaterials into or out of the pore volume of the biochar.

For example, FIG. 4a illustrates a schematic of one example of animplementation of biochar processing that includes washing the pores andboth pH and moisture adjustment. FIG. 4b illustrates yet another exampleof an implementation of biochar processing that includes inoculation.

As illustrated in FIG. 4a , raw biochar 402 is placed into a reactor ortank 404. A washing or treatment liquid 403 is then added to a tank anda partial vacuum, using a vacuum pump, 405 is pulled on the tank. Thetreating or washing liquid 403 may be used to clean or wash the pores ofthe biochar 402 or adjust the chemical or physical properties of thesurface area or pore volume, such as pH level, usable pore volume, orVOC content, among other things. The vacuum can be applied after thetreatment liquid 403 is added or while the treatment liquid 403 isadded. Thereafter, the washed/adjusted biochar 410 may be moistureadjusted by vacuum exfiltration 406 to pull the extra liquid from thewashed/moisture adjusted biochar 410 or may be placed in a centrifuge407, heated or subjected to pressure gradient changes (e.g., blowingair) for moisture adjustment. The moisture adjusted biochar 412 may thenbe bagged or subject to further treatment. Any excess liquids 415collected from the moisture adjustment step may be disposed of orrecycled, as desired. Optionally, biochar fines may be collected fromthe excess liquids 415 for further processing, for example, to create aslurry, cakes, or biochar extrudates. It should be noted that in any ofthese steps, the residual gaseous environment in the tanks orcentrifuges may be either ambient air, or a prescribed gas orcombination of gasses to impact (through assistance or attenuation)reactivity during the process.

Optionally, rather than using a vacuum pump 405, a positive pressurepump may be used to apply positive pressure to the tank 404. In somesituations, applying positive pressure to the tank may also function toforce or accelerate the washing or treating liquid 403 into the pores ofthe biochar 402. Any change in pressure in the tank 404 or across thesurface of the biochar could facilitate the exchange of gas and/ormoisture into and out of the pores of the biochar with the washing ortreating liquid 403 in the tank. Accordingly, changing the pressure inthe tank and across the surface of the biochar, whether positive ornegative, is within the scope of this invention. The atmosphere of thetank may be air or other gaseous mixture, prior to the intuition of thepressure change.

As illustrated FIG. 4b , the washed/adjusted biochar 410 or thewashed/adjusted and moisture adjusted biochar 412 may be further treatedby inoculating or impregnating the pores of the biochar with an additive425. The biochar 410, 412 placed back in a reactor 401, an additivesolution 425 is placed in the reactor 401 and a vacuum, using a vacuumpump, 405 is applied to the tank. Again, the vacuum can be applied afterthe additive solution 425 is added to the tank or while the additivesolution 425 is being added to the tank. Thereafter, the washed,adjusted and inoculated biochar 428 can be bagged. Alternatively, iffurther moisture adjustment is required, the biochar can be furthermoisture adjusted by vacuum filtration 406 to pull the extra liquid fromthe washed/moisture adjusted biochar 410 or may be placed in acentrifuge 407 for moisture adjustment. The resulting biochar 430 canthen be bagged. Any excess liquids 415 collected from the moistureadjustment step may be disposed of or recycled, as desired. Optionally,biochar particulates or “fines” which easily are suspended in liquid maybe collected from the excess liquids 415 for further processing, forexample, to create a slurry, biochar extrudates, or merely a biocharproduct of a consistently smaller particle size. As described above,both processes of the FIG. 4a and 4b can be performed with a surfactantsolution in place of, or in conjunction with, the vacuum 405.

While known processes exist for the above described processes, researchassociated with the present invention has shown improvement and theability to better control the properties and characteristics of thebiochar if the processes are performed through the infusion anddiffusion of liquids into and out of the biochar pores. One suchtreatment process that can be used is vacuum impregnation and vacuumand/or centrifuge extraction. Another such treatment process that can beused is the addition of a surfactant to infused liquid, which infusedliquid may be optionally heated, cooled, or used at ambient temperatureor any combination of the three.

Since research associated with the present invention has identified whatphysical and chemical properties have the highest impact on plant growthand/or soil health, the treatment process can be geared to treatdifferent forms of raw biochar to achieve treated biochar propertiesknown to enhance these characteristics. For example, if the pH of thebiochar needs to be adjusted to enhance the raw biochar performanceproperties, the treatment may be the infusion of an acid solution intothe pores of the biochar using vacuum, surfactant, or other treatmentmeans. This treatment of pore infusion through, for example, the rapid,forced infusion of liquid into and out the pores of the biochar, hasfurther been proven to sustain the adjusted pH levels of the treatedbiochar for much longer periods than biochar that is simply immersed inan acid solution for the same period of time. By way of another example,if the moisture content needs to be adjusted, then excess liquid andother selected substances (e.g. chlorides, dioxins, and other chemicals,to include those previously deposited by treatment to catalyze orotherwise react with substances on the interior or exterior surfaces ofthe biochar) can be extracted from the pores using vacuum and/orcentrifuge extraction or by using various heating techniques. The abovedescribes a few examples of treatment that result in treated biocharhaving desired performance properties identified to enhance soil healthand plant life or other applications.

FIG. 5 illustrates one example of a system 500 that utilizes vacuumimpregnation to treat raw biochar. Generally, raw biochar particles, andpreferably a batch of biochar particles, are placed in a reactor, whichis connected to a vacuum pump, and a source of treating liquid (i.e.water or acidic/basis solution). When the valve to the reactor isclosed, the pressure in the reactor is reduced to values ranging from750 Torr to 400 Torr to 10 Torr or less. The biochar is maintained undervacuum (“vacuum hold time”) for anywhere from seconds to 1 minute to 10minutes, to 100 minutes, or possibly longer. By way of example, forabout a 500 pound batch of untreated biochar, a vacuum hold time of fromabout 1 to about 5 minutes can be used if the reactor is of sufficientsize and sufficient infiltrate is available to adjust the necessaryproperties. While under the vacuum the treating liquid may then beintroduced into the vacuum chamber containing the biochar.Alternatively, the treating liquid may be introduced into the vacuumchamber before the biochar is placed under a vacuum. Optionally,treatment may also include subjecting the biochar to elevatedtemperatures from ambient to about 250° C. or reduced temperatures toabout −25° C. or below, with the limiting factor being the temperatureand time at which the infiltrate can remain flowable as a liquid orsemi-liquid.

The infiltrate or treating liquid is drawn into the biochar pore, andpreferably drawn into the macropores and mesopores. Depending upon thespecific doses applied and pore structure of the biochar, the infiltratecan coat anywhere from 10% to 50% to 100% of the total macropore andmesopore surface area and can fill or coat anywhere from a portion tonearly all (10%-100%) of the total macropore and mesopore volume.

As described above, the treating liquid can be left in the biochar, withthe batch being a treated biochar batch ready for packaging, shipmentand use in an agricultural or other application. The treating liquid mayalso be removed through drying, treatment with heated gases, subsequentvacuum processing, centrifugal force (e.g., cyclone drying machines orcentrifuges), dilution, or treatment with other liquids, with the batchbeing a treated biochar batch ready for packaging, shipment and use inan agricultural application. A second, third or more infiltration,removal, infiltration and removal, and combinations and variations ofthese may also be performed on the biochar with optional drying stepsbetween infiltrations to remove residual liquid from and reintroducegasses to the pore structure if needed. In any of these stages theliquid may contain organic or inorganic surfactants to assist with thepenetration of the treating liquid.

As illustrated in FIG. 5, a system 500 for providing a biochar,preferably having predetermined and generally uniform properties. Thesystem 500 has a vacuum infiltration tank 501. The vacuum infiltrationtank 501 has an inlet line 503 that has a valve 504 that seals the inletline 503. In operation, the starting biochar is added to vacuuminfiltration tank 501 as shown by arrow 540. Once the tank is filledwith the starting biochar, a vacuum is applied to the tank, by a vacuumpump connected to vacuum line 506, which also has valve 507. Thestarting biochar is held in the vacuum for a vacuum hold time.Infiltrate, as shown by arrow 548 is added to the tank 501 by line 508having valve 509. The infiltrate is mixed with the biochar in the tank501 by agitator 502. The mixing process is done under vacuum for aperiod of time sufficient to have the infiltrate fill the desired amountof pore volume, e.g., up to 100% of the macropores and mesopores.

Alternatively, the infiltrate may be added to the vacuum infiltrationtank 501 before vacuum is pulled on the tank. Optionally, one or moreselected gasses may be added to the tank. In this manner, infiltrate isadded in the tank in an amount that can be impregnated into the biocharand optionally, the gasses introduced can also potentially impact thereactivity of the liquid as well as any organic or inorganic substanceson the surface or in the pore volume of the biochar. As the vacuum isapplied, the biochar is circulated in the tank to cause the infiltrateto fill the pore volume. To one skilled in the art, it should be clearthat the agitation of the biochar during this process can be performedthrough various means, such as a rotating tank, rotating agitator,pressure variation in the tank itself, or other means. Additionally, thebiochar may be dried using conventional means before even the firsttreatment. This optional pre-drying can remove liquid from the pores andin some situations may increase the efficiency of impregnation due topressure changes in the tank.

Pressure is then restored in the tank 501 with either ambient air or aprescribed selection of gasses, and the infiltrated biochar is removed,as shown by arrow 541, from the tank 501 to bin 512, by way of a sealinggate 511 and removal line 510. The infiltrated biochar is collected inbin 512, where it can be further processed in several different ways.The infiltrated biochar can be shipped for use as a treated biochar asshown by arrow 543. The infiltrated biochar can be returned to the tank501 (or a second infiltration tank). If returned to the tank 501 thebiochar can be processed with a second infiltration step, a vacuumdrying step, a washing step, or combinations and variations of these.The infiltrated biochar can be moved by conveyor 514, as shown by arrow542, to a drying apparatus 516, e.g., a centrifugal dryer or heater,where water, infiltrate or other liquid is removed by way of line 517,and the dried biochar leaves the dryer through discharge line 518 asshown by arrow 545, and is collected in bin 519. The biochar is removedfrom the bin by discharge 520. The biochar may be shipped as a treatedbiochar for use in an agriculture application, as shown by arrow 547.The biochar may also be further processed, as shown by 546. Thus, thebiochar could be returned to tank 501 (or a second vacuum infiltrationtank) for a further infiltration step. The drying step may be repeatedeither by returning the dry biochar to the drying apparatus 516, or byrunning the biochar through a series of drying apparatus, until thepredetermined dryness of the biochar is obtained, e.g., between 50% toless than 1% moisture.

The system 500 is illustrative of the system, equipment and processesthat can be used for, and to carry out the present inventions. Variousother implementations and types of equipment can be used. The vacuuminfiltration tank can be a sealable off-axis rotating vessel, chamber ortank. It can have an internal agitator that also when reversed can movematerial out, empty it, (e.g., a vessel along the lines of a largecement truck, or ready mix truck, that can mix and move material out ofthe tank, without requiring the tank's orientation to be changed).Washing equipment may be added or utilized at various points in theprocess, or may be carried out in the vacuum tank, or drier, (e.g., washfluid added to biochar as it is placed into the drier for removal).Other steps, such as bagging, weighing, the mixing of the biochar withother materials, e.g., fertilized, peat, soil, etc. can be carried out.In all areas of the system referring to vacuum infiltration, optionallypositive pressure can be applied, if needed, to enhance the penetrationof the infiltrate or to assist with re-infusion of gaseous vapors intothe treated char. Additionally, where feasible, especially in positivepressure environments, the infiltrate may have soluble gasses addedwhich then can assist with removal of liquid from the pores, or gaseoustreatment of the pores upon equalization of pressure.

As noted above, the biochar may also be treated using a surfactant. Thesame or similar equipment used in the vacuum infiltration process can beused in the surfactant treatment process. Although it is not necessaryto apply a vacuum in the surfactant treatment process, the vacuuminfiltration tank or any other rotating vessel, chamber or tank can beused. In the surfactant treatment process, a surfactant, such as yuccaextract, is added to the infiltrate, e.g., acid wash or water. Thequantity of the surfactant added to the infiltrate may vary dependingupon the surfactant used. For example, organic yucca extract can beadded at a rate of between 0.1-20%, but more preferably 1-5% by volumeof the infiltrate. The infiltrate with surfactant is then mixed with thebiochar in a tumbler for several minutes, e.g., 3-5 minutes, withoutapplied vacuum. Optionally, a vacuum or positive pressure may be appliedwith the surfactant to improve efficiency and penetration, but is notstrictly necessary. Additionally, infiltrate to which the surfactant ordetergent is added may be heated or may be ambient temperature or less.Similarly, the mixture of the surfactant or detergent, as well as thechar being treated may be heated, or may be ambient temperature, orless. After tumbling, excess free liquid can be removed in the samemanner as described above in connection with the vacuum infiltrationprocess. Drying, also as described above in connection with the vacuuminfiltration process, is an optional additional step. Besides yuccaextract, a number of other surfactants may be used for surfactanttreatment, which include, but are not limited to, the following:nonionic types, such as, ethoxylated alcohols, phenols-lauryl alcoholethoxylates, Fatty acid esters-sorbitan, tween 20, amines,amides-imidazoles; anionic types, such as sulfonates-arylalkylsulfonates and sulfate-sodium dodecyl sulfate; cationic types, such asalkyl-amines or ammoniums-quaternary ammoniums; and amphoteric types,such as betaines-cocamidopropyl betaine. Additionally biosurfactants, ormicrobes which produce biosurfactants such as Flavobacterium sp. mayalso be used.

Optionally, the biochar may also be treated by applying ultrasonics. Inthis treatment process, the biochar may be contacted with a treatingliquid that is agitated by ultrasonic waves. By agitating the treatingliquid, contaminants may be dislodged or removed from the biochar due tobulk motion of the fluid in and around the biocarbon, pressure changes,including cavitation in and around contaminants on the surface, as wellas pressure changes in or near pore openings (cavitation bubbles) andinternal pore cavitation.

In this manner, agitation will cause contaminants of many forms to bereleased from the internal and external structure of the biochar. Theagitation also encourages the exchange of water, gas, and other liquidswith the internal biochar structure. Contaminants are transported fromthe internal structure to the bulk liquid (treating fluid) resulting inbiochar with improved physical and chemical properties. Theeffectiveness of ultrasonic cleaning is tunable as bubble size andnumber is a function of frequency and power delivered by the transducerto the treating fluid

In one example, applying ultrasonic treatment, raw wood based biocharbetween about 10 microns to 10 mm with moisture content from 0% to 90%may be mixed with a dilute mixture of acid and water (together thetreating liquid) in a processing vessel that also translates the slurry(the biochar/treating liquid mixture). During translation, the slurrypasses near an ultrasonic transducer to enhance the interaction betweenthe fluid and biochar. The biochar may experience one or multiple washesof dilute acid, water, or other treating fluids. The biochar may alsomake multiple passes by ultrasonic transducers to enhance physical andchemical properties of the biochar. For example, once a large volume ofslurry is made, it can continuously pass an ultrasonic device and bedegassed and wetted to its maximum, at a rapid processing rate. Theslurry can also undergo a separation process in which the fluid andsolid biochar are separated at 60% effectiveness or greater.

Through ultrasonic treatment, the pH of the biochar, or other physicaland chemical properties may be adjusted and the mesopore and macroporesurfaces of the biochar may be cleaned and enhanced. Further, ultrasonictreatment can be used in combination with bulk mixing with water,solvents, additives (fertilizers, etc.), and other liquid basedchemicals to enhance the properties of the biochar. After treatment, thebiochar may be subject to moisture adjustment, further treatment and/orinoculation using any of the methods set forth above. In certainapplications, ultrasonic technology may also be used to modify (usuallyreduce) the size of the biochar particles while retaining much, most, ornearly all of the porosity and pore structure. This yields smaller sizeparticles with different morphologies than other methods of sizing suchas grinding, crushing, sieving, or shaking.

C. Impact of Treatment

As illustrated above, the treatment process, whether using pressurechanges (e.g. vacuum), surfactant or ultrasonic treatment, or acombination thereof, may include two steps, which in certainapplications, may be combined: (i) washing and (ii) inoculation of thepores with an additive. When the desired additive is the same and thatbeing inoculated into the pores, e.g., water, the step of washing thepores and inoculating the pores with an additive may be combined.

While not exclusive, washing is generally done for one of threepurposes: (i) to modify the surface of the pore structure of the biochar(i.e., to allow for increased retention of liquids); (ii) to modify thepH of the biochar; and/or (iii) to remove undesired and potentiallyharmful compounds or gases.

Testing has further demonstrated that if the biochar is treated, atleast partially, in a manner that causes the infusion and/or effusion ofliquids and/or vapors into and/or out of the biochar pores (throughmechanical, physical, biological, or chemical means), certain beneficialproperties of the biochar can be altered, enhanced or improved throughtreatment. By knowing the properties of the raw biochar and the optimaldesired properties of the treated biochar, the raw biochar can then betreated in a manner that results in the treated biochar havingcontrolled optimized properties and greater levels of consistencybetween batches as well as between treated biochars arising from variousfeedstocks.

Using the treatment processes described above, or other treatments thatprovide, in part, for the infusion and/or effusion of liquids and/orvapors into and/or out of the biochar pores, biochars can have improvedphysical and chemical properties over raw biochar.

1. Water Holding/Retention Capacity

As demonstrated below, the treatment processes of the invention modifythe surfaces of the pore structure to provide enhanced functionality andto control the properties of the biochar to achieve consistent andpredicable performance. Using the above treatment processes, anywherefrom at least 10% of the total pore surface area up to 90% or more ofthe total pore surface area may be modified. In some implementations, itmay be possible to achieve modification of up to 99% or more of thetotal pore surface area of the biochar particle. Using the processes setforth above, such modification may be substantially and uniformlyachieved for an entire batch of treated biochar.

For example, it is believed that by treating the biochar as set forthabove, the hydrophilicity of the surface of the pores of the biochar ismodified, allowing for a greater water retention capacity. Further, bytreating the biochars as set forth above, gases and other substances arealso removed from the pores of the biochar particles, also contributingto the biochar particles' increased water holding capacity. Thus, theability of the biochar to retain liquids, whether water or additives insolution, is increased, which also increases the ability to load thebiochar particles with large volumes of inoculant, infiltrates and/oradditives.

A batch of biochar has a bulk density, which is defined as weight ingrams (g) per cm³ of loosely poured material that has or retains somefree space between the particles. The biochar particles in this batchwill also have a solid density, which is the weight in grams (g) per cm³of just particles, i.e., with the free space between the particlesremoved. The solid density includes the air space or free space that iscontained within the pores, but not the free space between particles.The actual density of the particles is the density of the material ingrams (g) per cm³ of material, which makes up the biochar particles,i.e., the solid material with pore volume removed.

In general, as bulk density increases the pore volume would be expectedto decrease and, if the pore volume is macro or mesoporous, with it, theability of the material to hold infiltrate, e.g., inoculant. Thus, withthe infiltration processes, the treated biochars can have impregnationcapacities that are larger than could be obtained without infiltration,e.g., the treated biochars can readily have 10%, 30%, 40%, 50%, or mostpreferably, 60%-100% of their total pore volume filled with aninfiltrate, e.g., an inoculant. The impregnation capacity is the amountof a liquid that a biochar particle, or batch of particles, can absorb.The ability to make the pores surface hydrophilic, and to infuse liquiddeep into the pore structure through the application of positive ornegative pressure and/or a surfactant, alone or in combination, providesthe ability to obtain these high impregnation capabilities. The treatedbiochars can have impregnation capacities, i.e., the amount ofinfiltrate that a particle can hold on a volume held/total volume of aparticle basis, that is greater than 0.2 cm³/cm³ to 0.8 cm³/cm³.

Accordingly, by using the treatment above, the water retention capacityof biochar can be greatly increased over the water retention capacitiesof various soil types and even raw biochar, thereby holding water and/ornutrients in the plant's root zone longer and ultimately reducing theamount of applied water (through irrigation, rainfall, or other means)needed by up to 50% or more. FIG. 6 has two charts showing the waterretention capacities of planting substrates versus when mixed with rawand treated biochar. In this example, the raw and treated biochar arederived from coconut biomass. The soils sampled are loam and sandy claysoil and a common commercial horticultural peat and perlite soillesspotting mix. The charts show the retained water as a function of time.

In chart A of FIG. 6, the bottom line represents the retained water inthe sandy claim loam soil over time. The middle line represents theretained water in the sandy clay soil with 20% by volume percent ofunprocessed raw biochar. The top line represents the retained water inthe sandy clay loam soil with 20% by volume percent of treated biochar(adjusted and inoculated biochar). Chart B of FIG. 6 represents the sameusing peat and perlite soilless potting mix rather than sandy clay loamsoil.

As illustrated in FIG. 7 the treated biochar has an increased waterretention capacity over raw biochar of approximately 1.5 times the rawbiochar. Similarly, testing of treated biochar derived from pine havealso shown an approximate 1.5 times increase in water retention capacityover raw biochar. With certain biochar, the water retention capacity oftreated biochar could be as great as three time that of raw biochar.

“Water holding capacity,” which may also be referred to as “WaterRetention Capacity,” is the amount of water that can be held bothinternally within the porous structure and in the interparticle voidspaces in a given batch of particles. While a summary of the method ofmeasure is provided above, a more specific method of measuring waterholding capacity/water retention capacity is measured by the followingprocedure: (i) drying a sample of material under temperatures of 105° C.for a period of 24 hours or using another scientifically acceptabletechnique to reduce the moisture content of the material to less than2%, less than 1%; and preferably less than 0.5% (ii) placing a measuredamount of dry material in a container; (iii) filling the containerhaving the measured amount of material with water such that the materialis completely immersed in the water; (iv) letting the water remain inthe container having the measured amount of material for at least tenminutes or treating the material in accordance with the invention byinfusing with water when the material is a treated biochar; (v) drainingthe water from the container until the water ceases to drain; (vi)weighing the material in the container (i.e., wet weight); (vii) againdrying the material by heating it under temperatures of 105° C. for aperiod of 24 hours or using another scientifically acceptable techniqueto reduce the moisture content of the material to less than 2% andpreferably less than 1%; and (viii) weighing the dry material again(i.e., dry weight) and, for purposes of a volumetric measure,determining the volume of the material.

Measured gravimetrically, the water holding/water retention capacity isdetermined by measuring the difference in weight of the material fromstep (vi) to step (viii) over the weight of the material from step(viii) (i.e., wet weight-dry weight/dry weight). FIG. 7 illustrates thedifferent water retention capacities of raw biochar versus treatedbiochar measured gravimetrically. As illustrated, water retentioncapacity of raw biochar can be less than 200%, whereas treated biocharcan have water retention capacities measured gravimetrically greaterthan 100%, and preferably between 200 and 400%.

Water holding capacity can also be measured volumetrically andrepresented as a percent of the volume of water retained in the biocharafter gravitationally draining the excess water/volume of biochar Thevolume of water retained in the biochar after draining the water can bedetermined from the difference between the water added to the containerand water drained off the container or from the difference in the weightof the wet biochar from the weight of the dry biochar converted to avolumetric measurement. This percentage water holding capacity fortreated biochar may be 30% and above by volume, and preferably 50-55percent and above by volume.

Given biochar's increased water retention capacity, the application ofthe treated biochar and even the raw biochar can greatly assist with thereduction of water and/or nutrient application. It has been discoveredthat these same benefits can be imparted to agricultural growth.

2. Plant Available Water

As illustrated in FIG. 8, plant available water is greatly increased intreated biochar over that of raw biochar. FIG. 8 illustrates the plantavailable water in raw biochar, versus treated biochar and treated driedbiochar and illustrates that treated biochar can have a plant availablewater percent of greater than 35% by volume.

“Plant Available Water” is the amount of unbound water in the materialavailable for plants to uptake. This is calculated by subtracting thewater content at permanent wilting point from the water content at fieldcapacity, which is the point when no water is available for the plants.Field capacity is generally expressed as the bulk water content retainedat −33 J/kg (or −0.33 bar) of hydraulic head or suction pressure.Permanent wilting point is generally expressed as the bulk water contentretained at −1500 J/kg (or −15.0 bar) of hydraulic head or suctionpressure. Methods for measuring plant available water are well-known inthe industry and use pressure plate extractor, which are commerciallyavailable or can be built using well-known principles of operation.

3. Remaining Water Content

Treated biochar of the present invention has also demonstrated theability to retain more water than raw biochar after exposure to theenvironment for defined periods of time. For purposes of thisapplication “remaining water content” can be defined as the total amountof water that remains held by the biochar after exposure to theenvironment for certain amount of time. Exposure to environment isexposure at ambient temperature and pressures. Under this definition,remaining water content can be may be measured by (i) creating a sampleof biochar that has reached its maximum water holding capacity; (ii)determining the total water content by thermogravimetric analysis (H2O(TGA)), as described above on a sample removed from the output of step(i) above, (iii) exposing the biochar in the remaining sample to theenvironment for a period of 2 weeks (15 days, 360 hrs.); (iv)determining the remaining water content by thermogravimetric analysis(H2O (TGA)); and (v) normalizing the remaining (retained) water in mL to1 kg or 1 L biochar. The percentage of water remaining after exposurefor this two-week period can be calculated by the remaining watercontent of the biochar after the predetermine period over the watercontent of the biochar at the commencement of the two-week period. Usingthis test, treated biochar has shown to retain water at rates over 4×that of raw biochar. Testing has further demonstrated that the followingamount of water can remain in treated biochar after two weeks ofexposure to the environment: 100-650 mL/kg; 45-150 mL/L; 12-30 gal/ton;3-10 gal/yd3 after 360 hours (15 days) of exposure to the environment.In this manner, and as illustrated in FIG. 12, biochar treated throughvacuum impregnation can increase the amount of retained water in biocharabout 3× compared to other methods even after seven weeks. In general,the more porous and the higher the surface area of a given material, thehigher the water retention capacity. Further, it is theorized that bymodifying the hydrophilicity/hydrophobicity of the pore surfaces,greater water holding capacity and controlled release may be obtained.Thus, viewed as a weight percent, e.g., the weight of retained water toweight of biochar, examples of the present biochars can retain more than5% of their weight, more than 10% of their weight, and more than 15% oftheir weight, and more compared to an average soil which may retain 2%or less, or between 100-600 ml/kg by weight of biochar

Tests have also shown that treated biochars that show weight loss of >1%in the interval between 43-60° C. when analyzed by the ThermalGravimetric Analysis (TGA) (as described below) demonstrate greaterwater holding and content capacities over raw biochars. Weight lossof >5%-15% in the interval between 38-68° C. when analyzed by theThermal Gravimetric Analysis (TGA) using sequences of time andtemperature disclosed in the following paragraphs or others may also berealized. Weight percentage ranges may vary from between >1%-15% intemperature ranges between 38-68° C., or subsets thereof, to distinguishbetween treated biochar and raw biochar.

FIG. 9 is a chart 900 showing the weight loss of treated biochars 902verses raw biochar samples 904 when heated at varying temperatures usingthe TGA testing described below. As illustrated, the treated biochars902 continue to exhibit weight loss when heated between 40-60° C. whenanalyzed by the Thermal Gravimetric Analysis (TGA) (described below),whereas the weight loss in raw biochar 904 between the same temperatureranges levels off. Thus, testing demonstrates the presence of additionalmoisture content in treated biochars 902 versus raw biochars 904.

In particular, the treated biochars 902 exhibit substantial water losswhen heated in inert gas such as nitrogen. More particularly, whenheated for 25 minutes at each of the following temperatures 20, 30, 40,50 and 60 degrees Celsius, ° C. the treated samples lose about 5-% to15% in the interval 43-60° C. and upward of 20-30% in the intervalbetween 38-68° C. The samples to determine the water content of the rawbiochar were obtained by mixing a measured amount of biochar and water,stirring the biochar and water for 2 minutes, draining off the water,measuring moisture content and then subjecting the sample to TGA. Thesamples for the treated biochar were obtained by using the same measuredamount of biochar as used in the raw biochar sample, and impregnatingthe biochar under vacuum. Similar results are expected with biochartreated with a treatment process consistent with those described in thisdisclosure with the same amount of water as used with the raw biochar.The moisture content is then measured and the sample is subjected to TGAdescribed above.

The sequences of time and temperature conditions for evaluating theeffect of biochars heating in inert atmosphere is defined in thisapplication as the “Bontchev-Cheyne Test” (“BCT”). The BCT is run usingsamples obtained, as described above, and applying Thermal GravimetricAnalysis (TGA) carried out using a Hitachi STA 7200 analyzer undernitrogen flow at the rate of 110 mL/min. The biochar samples are heatedfor 25 minutes at each of the following temperatures: 20, 30, 40, 50 and60° C. The sample weights are measured at the end of each dwell step, atthe beginning and at the end of the experiment. The analyzer alsocontinually measures and records weight over time. Biochars havingenhanced water holding or retention capacities are those that exhibitweight loss of >5% in the interval between 38-68° C., >1% in theinterval between 43-60° C. Biochars with greater water holding orretention capacities can exhibit >5% weight loss in the interval between43-60° C. measured using the above described BCT.

D. Impregnation and/or Inoculation with Infiltrates or Additives

In addition to mitigating or removing deleterious pore surfaceproperties, by treating the pores of the biochar through a forced,assisted, accelerate or rapid infiltration process, such as thosedescribed above, the pore surface properties of the biochar can beenhanced. Such treatment processes may also permit subsequentprocessing, may modify the pore surface to provide predeterminedproperties to the biochar, and/or provide combinations and variations ofthese effects. For example, it may be desirable or otherwiseadvantageous to coat substantially all, or all of the biochar macroporeand mesopore surfaces with a surface modifying agent or treatment toprovide a predetermined feature to the biochar, e.g., surface charge andcharge density, surface species and distribution, targeted nutrientaddition, magnetic modifications, root growth facilitator, and waterabsorptivity and water retention properties.

By infusing liquids into the pores of biochar, it has been discoveredthat additives infused within the pores of the biochar provide a timerelease effect or steady flow of some beneficial substances to the rootzones of the plants and also can improve and provide a more beneficialenvironment for microbes which may reside or take up residence withinthe pores of the biochar. In particular, additive infused biocharsplaced in the soil prior to or after planting can dramatically reducethe need for high frequency application of additives, minimize lossescaused by leaching and runoff and/or reduce or eliminate the need forcontrolled release fertilizers. They can also be exceptionallybeneficial in animal feed applications by providing an effectivedelivery mechanism for beneficial nutrients, pharmaceuticals, enzymes,microbes, or other substances.

For purposes of this application, “infusion” of a liquid or liquidsolution into the pores of the biochar means the introduction of theliquid or liquid solution into the pores of the biochar by a means otherthan solely contacting the liquid or solution with the biochar, e.g.,submersion. The infusion process, as described in this application inconnection with the present invention, includes a mechanical, chemicalor physical process that facilitates or assist with the penetration ofliquid or solution into the pores of the biochar, which process mayinclude, but not be limited to, positive and negative pressure changes,such as vacuum infusion, surfactant infusion, or infusion by movement ofthe liquid and/or biochar (e.g., centrifugal force, steam and/orultrasonic waves) or other method that facilitates, assists, forces oraccelerates the liquid or solution into the pores of the biochar. Priorto infusing the biochar, the biochar, as described in detail above, maybe washed and/or moisture adjusted.

FIG. 10 is a flow diagram 1000 of one example of a method for infusingbiochar with an additive. Optionally, the biochar may first be washed ortreated at step 1002, the wash may adjust the pH of the biochar, asdescribed in more detail above, or may be used to remove elemental ashand other harmful organics that may be unsuitable for the desiredinfused fertilizer. Optionally, the moisture content of the biochar maythen be adjusted by drying the biochar at step 1004, also as describedin further detail above, prior to infusion of the additive or inoculantat step 1006.

In summary, the infusion process may be performed with or without anywashing, prior pH adjustment or moisture content adjustment. Optionally,the infusion process may be performed with the wash and/or the moistureadjustment step. All the processes may be completed alone or in theconjunction with one or more of the others.

Through the above process of infusing the additive into the pores of thebiochar, the pores of the biochar may be filled by 25%, up to 100%, withan additive solution, as compared to 1-20% when the biochar is onlysubmerged in the solution or washed with the solution for a period ofless than twelve hours. Higher percentages may be achieved by washingand/or drying the pores of the biochar prior to infusion.

Data have been gathered from research conducted comparing the results ofsoaking or immersion of biochar in liquid versus vacuum impregnation ofliquid into biochar. These data support the conclusion that vacuumimpregnation provides greater benefits than simple soaking and resultsin a higher percentage volume of moisture on the surface, interstitiallyand in the pores of the biochar.

In one experiment, equal quantities of pine biochar were mixed withequal quantities of water, the first in a beaker, the second in a vacuumflask. The mixture in the beaker was continuously stirred for up to 24hours, then samples of the suspended solid were taken, drained andanalyzed for moisture content. The mixture in the vacuum flask wasconnected to a vacuum pump and negative pressure of 15″ was applied.Samples of the treated solid were taken, drained and analyzed formoisture content. FIG. 11 is a chart illustrating the results of theexperiment. The lower graph 1102 of the chart, which shows the resultsof soaking over time, shows a wt. % of water of approximately 52%. Theupper graph 1104 of the chart, which shows the results of vacuumimpregnation over time, shows a wt. % of water of approximately 72%.

FIGS. 12a and 12b show two charts that further illustrate that the totalwater and/or any other liquid content in processed biochar can besignificantly increased using vacuum impregnation instead of soaking.FIG. 12a compares the mL of total water or other liquid by retained by 1mL of treated pine biochar. The graph 1202 shows that approximately 0.17mL of water or other liquid are retained through soaking, while thegraph 1204 shows that approximately 0.42 mL of water or other liquid areretained as a result of vacuum impregnation. FIG. 12b shows that theretained water of pine biochar subjected to soaking consists entirely ofsurface and interstitial water 1206, while the retained water of pinebiochar subjected to vacuum impregnation consists not only of surfaceand interstitial water 1208 a, but also water impregnated in the poresof the biochar 1208 b.

In addition, as illustrated by FIG. 13, the amount of moisture contentimpregnated into the pores of vacuum processed biochars by varying theapplied (negative) pressure during the treatment process. The graphs offour different biochars all show how the liquid content of the pours ofeach of them increase to 100% as vacuum reactor pressure is increased.

In another experiment, the percentage of water retained in the pores ofpine derived biochar was measured to determine the difference inretained water in the pores of the biochar (i) soaked in water, and (ii)mixed with water subjected to a partial vacuum. For the soaking, 250 mLof raw biochar was mixed with 500 mL water in a beaker. Upon continuousstirring for 24 hrs., aliquots of the suspended solid were taken,drained on a paper towel and analyzed for moisture content. For thevacuum, 250 mL of raw biochar was mixed with 500 mL water in a vacuumflask. The flask was connected to a vacuum pump and negative pressure of15″ has been applied, aliquots of the treated solid were taken, drainedon a paper towel and analyzed for moisture content.

The total retained water amounts were measured for each sample. For thesoaked biochar, the moisture content of biochar remains virtuallyconstant for the entire duration of the experiment, 52 wt. % (i.e. 1 gof “soaked biochar” contains 0.52 g water and 0.48 g “dry biochar”).Taking into account the density of raw biochar, 0.16 g/cm³ (or mL), thevolume of the 0.48 g “dry biochar” is 3.00 mL (i.e. 3 mL dry biochar can“soak” and retain 0.52 mL water, or 1 mL dry biochar can retain 0.17 mLwater (sorbed on the surface and into the pores)).

For vacuum, the moisture content of the biochar remains virtuallyconstant for the entire duration of the experiment, 72 wt. %, (i.e. 1 gof vacuum impregnated biochar contains 0.72 g water and 0.28 g “drybiochar”). Taking into account the density of raw biochar, 0.16 g/cm³(or mL), the volume of the 0.28 g “dry biochar” is 1.75 mL (i.e. 1.75 mLdry biochar under vacuum can “absorb” and retain 0.72 mL water, or 1 mLdry biochar can retain 0.41 mL water (sorbed on the surface and into thepores)).

It was next determined where the water was retained—in the pores or onthe surface of the biochar. Capillary porosity (“CP”) (vol % inside thepores of the biochar), non-capillary porosity (“NCP”) (vol. %outside/between the particles), and the total porosity (CP+NCP)) weredetermined. Total porosity and non-capillary porosity were analyticallydetermined for the dry biochar and then capillary porosity wascalculated.

Since the dry biochar used in this experiment had a density less thanwater, the particles could be modeled and then tested to determine ifsoaking and/or treating the biochar could infuse enough water to makethe density of the biochar greater than that of water. Thus, the drybiochar would float and, if enough water infused into the pores, thesoaked or treated biochar would sink. Knowing the density of water andthe density of the biochar, calculations were done to determine thepercentage of pores that needed to be filled with water to make thebiochar sink. In this specific experiment, these calculations determinedthat more than 24% of the pore volume would need to be filled with waterfor the biochar to sink. The two processed biochars, soaked and vacuumtreated, were then immersed in water after 1 hour of said processing.The results of the experiment showed that the vast majority of thesoaked biochar floated and remained floating after 3 weeks, while thevast majority of the vacuum treated biochar sank and remained at thebottom of the water column after 3 weeks.

Using the results of these experiments and model calculations, thebiochar particles can be idealized to estimate how much more water is inthe pores from the vacuum treatment versus soaking. Since the externalsurface of the materials are the same, it was assumed that the samplesretain about the same amount of water on the surface. Then the mostconservative assumption was made using the boundary condition forparticles to be just neutral, i.e. water into pores equal 24%, the waterdistribution is estimated as follows:

VACUUM DRY SOAKED TREATED BIOCHAR BIOCHAR BIOCHAR Experimental resultFLOATED FLOATED SANK Total water (determined in 0% 52% 72% first part ofexperiment) Water in the pores (assumed 0% 24% 44% for floating biocharto be boundary condition, calculated for biochar that sank) Water on thesurface 0% 28% 28% (calculated for floating biochar, assumed to matchfloating biochar for the biochar that sank)

In summary, these experimental tests and model calculations show thatthrough vacuum treatment more than 24% of the pores of the biochar canbe filled with water and in fact at least 1.8 times the amount of watercan be infused into the pores compared to soaking. Vacuum treatment canimpregnate almost two times the amount of water into the pores for 1minute, while soaking does not change the water amount into the poresfor three weeks.

The pores may be substantially filled or completely filled withadditives to provide enhanced performance features to the biochar, suchas increased plant growth, nutrient delivery, water retention, nutrientretention, disadvantageous species control, e.g., weeds, disease causingbacteria, insects, volunteer crops, etc. By infusing liquid into thepore structure through the application of positive or negative pressure,surfactant and/or ultrasonic waves, alone or in combination, providesthe ability to impregnate the mesopores and macropores of the biocharwith additives, that include, but are not limited to, soil enhancingsolutions and solids.

The additive may be a soil enhancing agent that includes, but is not belimited to, any of the following: water, water solutions of salts,inorganic and organic liquids of different polarities, liquid organiccompounds or combinations of organic compounds and solvents, mineral andorganic oils, slurries and suspensions, supercritical liquids,fertilizers, PGPB (including plant growth promoting rhizobacteria,free-living and nodule-forming nitrogen fixing bacteria, organicdecomposers, nitrifying bacteria, and phosphate solubilizing bacteria),biocontrol agents, bioremediation agents, saprotrophic fungi,ectomycorrhizae and endomycorrhizae, among others.

Fertilizers that may be infused into the biochar include, but are notlimited to, the following sources of nitrogen, phosphorous, andpotassium: urea, ammonium nitrate, calcium nitrate, sulfur, ammoniumsulfate, monoammonium phosphate, ammonium polyphosphate, potassiumsulfate, or potassium chloride.

Similar beneficial results are expected from other additives, such as:bio pesticides; herbicides; insecticides; nematicides; plant hormones;plant pheromones; organic or inorganic fungicides; algicides;antifouling agents; antimicrobials; attractants; biocides, disinfectantsand sanitizers; miticides; microbial pesticides; molluscicides;bacteriacides; fumigants; ovicides; repellents; rodenticides,defoliants, desiccants; insect growth regulators; plant growthregulators; beneficial microbes; and, microbial nutrients or secondarysignal activators, that may also be added to the biochar in a similarmanner as a fertilizer. Additionally, beneficial macro- andmicro-nutrients such as, calcium, magnesium, sulfur, boron, zinc, iron,manganese, molybdenum, copper and chloride may also be infused into thebiochar in the form of a water solution or other solvent solution.

Examples of compounds, in addition to fertilizer, that may be infusedinto the pores of the biochar include, but are not limited to:phytohormones, such as, abscisic acid (ABA), auxins, cytokinins,gibberellins, brassinosteroies, salicylic acid, jasmonates, planetpeptide hormones, polyamines, karikins, strigolactones;2,1,3-Benzothiadiazole (BTH), an inducer of systemic acquired resistancethat confers broad spectrum disease resistance (including soil bornepathogens); signaling agents similar to BTH in mechanism or structurethat protects against a broad range or specific plant pathogens; EPSPSinhibitors; synthetic auxins; photosystem I inhibitors photosystem IIinhibitors; and HPPD inhibitors. Growth media, broths, or othernutrition to support the growth of microbes or microbial life may alsobe infused such as Lauryl Tryptose broth, glucose, sucrose, fructose, orother sugars or micronutrients known to be beneficial to microbes.Binders or binding solutions can also be infused into the pores to aidin the adhesion of coatings, as well as increasing the ability for thetreated biochar to associate or bond with other nearby particles in seedcoating applications. Infusion with these binders can also allow for thecoating of the biochar particle itself with other beneficial organismsor substances.

In one example, a 1000 ppm NO₃ ⁻ N fertilizer solution is infused intothe pores of the biochar. As discussed above, the method to infusebiochar with the fertilizer solution may be accomplished generally byplacing the biochar in a vacuum infiltration tank or other sealablerotating vessel, chamber or tank. When using vacuum infiltration, avacuum may be applied to the biochar and then the solution may beintroduced into the tank. Alternatively, the solution and biochar mayboth be introduced into the tank and, once introduced, a vacuum isapplied. Based upon the determined total pore volume of the biochar orthe incipient wetness, the amount of solution to introduce into the tanknecessary to fill the pore of the biochar can be determined. Wheninfused in this manner, significantly more nutrients can be held in agiven quantity of biochar versus direct contact of the biochar with thenutrients alone.

When using a surfactant, the biochar and additive solution may be addedto a tank along with 0.01-20% of surfactant, but more preferably 1-5% ofsurfactant by volume of fertilizer solution. The surfactant or detergentaids in the penetration of the wash solution into the pores of thebiochar. The same or similar equipment used in the vacuum infiltrationprocess can be used in the surfactant treatment process. Although it isnot necessary to apply a vacuum in the surfactant treatment process, thevacuum infiltration tank or any other rotating vessel, chamber or tankcan be used. Again, while it is not necessary to apply a vacuum, avacuum may be applied or the pressure in the vessel may be changed.Further, the surfactant can be added with or without heat or coolingeither of the infiltrate, the biochar, the vessel itself, or anycombination of the three.

The utility of infusing the biochar with fertilizer is that the pores inbiochar create a protective “medium” for carrying the nutrients to thesoil that provides a more constant supply of available nutrients to thesoil and plants and continues to act beneficially, potentially sorbingmore nutrients or nutrients in solution even after introduction to thesoil. By infusing the nutrients in the pores of the biochar, immediateoversaturation of the soil with the nutrients is prevented and a timereleased effect is provided. This effect is illustrated in connectionwith FIGS. 14 and 15. As demonstrated in connection with FIGS. 14 & 15below, biochars having pores infused with additives, using the infusionmethods described above, have been shown to increase nutrient retention,increase crop yields and provide a steadier flow of fertilizer to theroot zones of the plants. In fact, the interior and exterior surfaces ofthe biochar may be treated to improve their sorption and exchangecapabilities for the targeted nutrients prior to inoculation orinfusion. This is the preferred approach as it allows for the tailoringof the surfaces to match the materials being carried. An example wouldbe to treat the surfaces to increase the anionic exchange capacity wheninfusing with materials which typically manifest as anions, such asnitrates.

D. Coating Seeds

Given biochar's increased water retention capacities, the application ofthe treated biochar and even the raw biochar greatly assists with thereduction of water and/or nutrient application, and the ability ofbiochar to carry nutrients, microbes, both, or a combination of theseand other beneficial substances. It has been discovered that these samebenefits can be imparted to plant growth by coating the seeds themselveswith biochar prior to planting as well as providing a more efficient wayof delivering the biochar to the area of the germinating seed. Coatingthe seeds prior to planting, can dramatically reduce the need for highfrequency saturation watering in the period immediately followinginstallation. Coating particles with biochar can provide a moreefficient biochar delivery system.

The present invention includes a method for coating the seeds with thebiochar. In one example, the method to coat the seeds with biochar maybe accomplished generally by (i) creating a slurry of biochar and starchbinder, (ii) immersing the seeds in the slurry, and (iii) then dryingthe seeds.

FIG. 16 is a flow diagram 1600 of another example of a method that maybe used for coating seeds with biochar. As illustrated in FIG. 16, thesteps comprise: (i) preparing a starch solution (or binding solution) bymixing a starch (or a binder) with water to create a solution, step1602; (ii) heating the starch solution to dissolve the starch, step1604; (iii) placing seeds in a rotary tumbler, step 1606; (iv)dispensing the starch solution into the tumbler to coat seeds in amanner that lightly introduces the solution to the tumbler, step 1608;(v) tumbling the seeds until the seeds are evenly coated with the starchsolution, step 1610; (vi) dispensing biochar in the tumbler to coat theseeds with biochar, step 1612; and (vi) drying the coated seeds whiletumbling, step 1614.

At step 1602, the starch solution is prepared by mixing a starch orother binder with water. If the hydrophobicity of the biochar has beenreduced during treatment, water alone can also be used as a binder. Cornstarch is a simple example of a type of starch that may be used,although one skilled in the art will realize that there are many bindersthat can be used, such as starches, sugars, gum arabic, cellulose, clay,or polymers such as vinyl polymers, or a combination of these. Thebinder solution may be prepared by mixing enough corn starch withdeionized H₂O to create a solution. For example, the starch may beapproximately 2% by weight, but may range from 0.5% to 10% of starch byweight.

Those skilled in the art will recognize that another starch, besidescorn starch may be used as a binder. Additionally, other binders may beused with the restriction that they may not be phytotoxic and must besuitable for introduction into soil or other environments where seedsare germinated and the resulting seedlings are matured. Some examples ofthese other binders are gelatins, cellulose, sugars, or combinationsthereof. The binding solution can be made from a starch or other type ofbinder. According, the starch solution and starch, in the illustratedexample, are only one type of binding solution or binder that may beused in connection with the present invention.

In this particular embodiment, at step 1604, the starch solution is thenheated to dissolve the starch. At step 1606, the seeds are then placedin a tumbler, such as a rotary tumbler. The seeds may be weighed priorto placement in the tumbler. A variable speed tumbler may be used tohelp facilitate the mixing.

At step 1606, the seeds are placed in a rotary tumbler and the tumbleris prepared for introduction of the starch (or other binder) solution.The seeds are then lightly sprayed with starch solution and tumbled withthe starch solution until they are evenly coated with the starch/bindersolution.

Thereafter, at step 1610, the biochar may be added to the tumbler. Priorto adding to the tumbler, the biochar may be prepared by reducing it toa power if the particle size is not already desirable, by eithershifting or reducing the particle size of the biochar to one that issuitable for seed coating. If needed, the biochar may be pulverized toan average particle size of <1 mm. The size of the biochar particles maybe adapted to the size of the seeds being coated, with larger seedsoptionally utilizing larger particle sizes. As mentioned previously, themethod of sizing the biochar may be grinding, pulverizing, crushing,fracturing using ultrasonic, chemical, thermal, or pressure mechanisms,sieving, hydrodynamically sorting, attritting, or any combination ofthese.

Prior to adding the biochar, if necessary, the powered biochar may bedried at a temperature of at or about 120 degrees C. Additionally,beneficial macro- and micro-nutrients such as nitrogen, phosphorous,potassium, calcium, magnesium, sulfur, boron, zinc, iron, manganese,molybdenum, copper and chloride or starter fertilizers using ammoniumnitrate, ammonium sulfate, monoammonium phosphate, or ammoniumpolyphosphate with added micronutrients can be added to the mixture atthis time. Optionally, the biochar may have been already infused withthese nutrients, beneficial microbes, or even the binder solution itselfduring the treatment process outlined earlier. In some applications, thebiochar may have already been infused with a substance that will reactwith the binder added in this step to provide a more functional twostage biodegradable adhesive such as those outlined in U.S. Pat. No.8,895,052 or others which perform in similar manner. These types ofadhesives function in a similar manner to common epoxies, butdemonstrate biodegradable characteristics that may make them moresuitable for agricultural applications.

The mixture may also be heated or cooled during this stage to enhance orimprove either the performance of the binder or maintain the inoculant(if used) at a proper temperature to assure efficacy. When adding to thetumbler, the powered biochar is sprinkled or otherwise dispensed intothe tumbler until the seeds are coated, step 1612.

If a thicker coating of biochar is desired, then steps 1608 and 1610 maybe repeated. Each of the layers of biochar may optionally be infusedwith the same, different, or zero nutrients, microbes, or otherbeneficial substances, causing the layers the be the same or causingthem to be different or varied. The seeds may be sprayed with starchsolution again and allowed to tumble until evenly coated. If nutrientsare added, they may also be layered during this process such thatnutrients most beneficial to early germination and seedling growth areincorporated onto the biochar coated seeds. Then, more biochar mixturemay be added to the tumbler to increase the coating thickness until thedesired coating thickness is achieved. For example, these steps may berepeated, as necessary, to assure consistent coating to an averagethickness of 0.01 to 100 times the diameter of the seed.

Once the desired coating thickness is achieved, the coated seeds maythen be dried, for example, by tumbling at ambient temperature for aperiod of 12 hours, step 1612. Once dried, the coated seeds may then beremoved from the tumbler and prepared for packing. An example of the endproduct is illustrated in the image attached as FIG. 17.

Optionally, a fertilizer, nutrient or microbial carrier (other thanbiochar) may be added to coat the seeds in any of the layers. If afertilizer is desired, the fertilizer may be pulverized to prepare foraddition. The pulverized fertilizer may be added with the biochar or maybe added separately, using a different coating step from that of thebiochar. Like the biochar, the fertilizer, when added, is dispensed toallow for even coating of the seeds and is tumbled with seed foradequate time to disperse evenly across the seeds. The fertilizer mayalso be pulverized to an average particle size of <1 mm beforedispensing. Examples of fertilizers that may be added to the coat,include, but are not limited to the following: ammonium nitrate,ammonium sulfate, monoammonium phosphate, ammonium polyphosphate,Cal-Mag fertilizers or micronutrient fertilizers. Other additives, suchas fungicides, insecticides, nematicides, plant hormones, beneficialmicrobial spores, or secondary signal activators, may also be added tothe coating in a similar manner as a fertilizer, the inclusion of whichdoes not depart from the scope of the invention.

The above is only one example of how seeds may be coated with biocharprior to use as a soil amendment. Those skilled in the art willrecognize that there are many other mechanisms and processes that may beused to coat seeds without departing from the scope of the invention.Those skilled in the art will further recognize that the presentinvention can be used on any type of plant seed, including, but notlimited to, the following: grass, corn, wheat, soybeans, sugar beet,ornamental plant, vegetable, such as tomato, cucumber, squash, orlettuce, or any other plant commonly grown from seeds. For purposes ofthis application, grass seeds shall include all types of grass seeds.

When the coated seeds are grass seeds, the coated seeds may then beapplied using normal seeding techniques at the rate of between 500-1000lbs. per acre for lawns or ornamental applications, ranges of between 15and 4000 lbs. per acre may also be used without departing from the scopeof the invention. For pasture grass applications, the application rateis typically lower, generally between 15-100 lbs. per acre.

The utility of coating the seeds with the biochar is that the biocharcreates a protective “oasis” of water and nutrient retention around theseed to provide a more constant supply of available water and nutrientsto the seedling during germination and initial growth. Coating seedsalso allows for much easier application of biochar to the turfenvironment. It should be noted that coated seeds can also be used in“overseeding” applications for existing turf—namely applications whereseeds are added to either increase the density of existing turf, or toestablish an annual turf (e.g. rye) during a season where the perennialturf is dormant. Additionally, the seeds may be coated with treatedbiochar pre-infused with either nutrients, or microbial agents, such asmycorrhizal fungi, biocontrol bacteria or fungus, plant growth promotingrhizobacteria, mineral solubilizing microorganisms, or other microbeswhich demonstrate efficacy in turf grass environments.

The biochar increases the water and nutrient holding capacity of theimmediate surroundings of the seed. Biochar applied in the mannerdescribed above results in more vigorous root development and increasedestablishment time leading to healthier plants with increased diseaseresistance compared to plants from seeds absent the biochar coating.Coating seeds in this manner can also be a greatly improved mechanismfor delivery of both biochar as well as any nutrient or microbe infusedinto the biochar into the soil as the delivery can be accomplishedsimultaneously with the delivery of the seed into the soil.

Furthermore, the present invention may be used to coat other particles,besides seeds, with biochar. A solid or semi-solid particle, such as asmall stone, polymer bead, biodegradable plastic pellet, fragment of amineral such as perlite, or other particle that displays generallyuniform distribution in particle size when seen in aggregation may becoated in the same manner as the seeds (described above) to assist withthe distribution of biochar, or treated biochar, in a more efficientmanner. This method may be used to produce biochar pellets in a mannerthat does not rely on heat or pressure treatment. Thus, coatingparticles, as set forth above, can avoid many issues associated withmaintaining efficacy of microbes or less stable nutrients or microbialenergy sources when making pellets from biochar or treated biocharwithout a core particle.

Additionally, the particle coated may also be an ingestible particle,such as animal feed pellets, medicines, vitamins or other nutrients orfeed particles. Coating such ingestible particles with biochar ortreated biochar may assist in the addition of biochar or treated biocharinto the animal food chain and assist in the use of the biochar ortreated biochar in animal health applications. When coating aningestible particle, additives may also be included with or infused intopores of the coated biochar, through mixing, treatment, or both. By wayof example only, particles for use in the present invention may be anytype of particles that can be safely ingested or safely used inconnection with agricultural applications. Optimally, such particleswill range in size from 50 to 0.001 millimeters in diameter.

FIG. 18 illustrates one example of a cross-section of a coated particle1800 of the present invention. As illustrated in FIG. 18, the particle1802, which may be seed other particle suitable for the delivery ofbiochar for an intended purposes, may be substantially coated with alayer of biochar 1804. While FIG. 18 only illustrates one layer ofcoating, as described above, it is within the scope of the invention tocoat the particle with one or more layers of biochar, which layers mayfurther include water, other nutrients or other additives as set forthabove. The water, nutrients and/or additives may be mixed with thebiochar, added separately from the biochar, or infused into the biocharthrough the various treatment methods, as described previously.

The foregoing description of implementations has been presented forpurposes of illustration and description. It is not exhaustive and doesnot limit the claimed inventions to the precise form disclosed.Modifications and variations are possible in light of the abovedescription or may be acquired from practicing the invention. The claimsand their equivalents define the scope of the invention.

We claim:
 1. A method for coating particles, the method comprising thesteps of (i) preparing a binding solution by mixing a binder with water;(ii) heating the binding solution to dissolve the binder in the water;(iii) placing particles in a rotary tumbler; (iv) dispensing the bindingsolution into the tumbler with the particles; (v) tumbling the particlesuntil the particles are evenly coated with the binding solution; (vi)dispensing biochar in the tumbler to coat the particles with biochar;and (vi) drying the particles while tumbling.
 2. The method of claim 1where the biochar is reduced in size to an average particle size of <1mm before dispensing in the tumbler.
 3. The method of claim 1 furtherincluding the step of dispensing a fertilizer in the tumbler to coat theparticle.
 4. The method of claim 1 further including the step ofcombining a fertilizer with the biochar prior to dispensing the biocharinto the tumbler to coat the particles, whereby a combined mixture ofbiochar and fertilizer in dispensed into the tumbler to coat theparticles.
 5. The method of claim 3 where the fertilizer is reduced insize to an average particle size of <1 mm before dispensing in thetumbler.
 6. The method of claim 1 where the step of dispensing thebinding solution, tumbling the particles and dispensing the biochar inthe tumbler is repeated until the coat substantially surrounding theparticles is between 0.01 and 100 times the diameter of the particles.7. The method of claim 21 where the biochar, prior to being dispensed inthe tumbler, has been treated by the infusion of one or more liquidsinto pores of the biochar.
 8. The method of claim 7 where the infusionof one or more liquids into pores of the biochar is accomplished atleast in part by a vacuum processing treatment.
 9. The method of claim 7where the infusion of one or more liquid into pores of the biochar isaccomplished at least in part by a surfactant infusion treatment. 10.The method of claim 4 where the step of dispensing the binding solution,tumbling the particles and dispensing the mixture of fertilizer andbiochar in the tumbler is repeated until the coat substantiallysurrounding the particles is between 0.01 and 100 times the diameter ofthe particles.
 11. The method of claim 1 where the binder is one or moresubstances selected from the group comprising: a starch, sugar, gumarabic, cellulose, clay, and polymer.
 12. The method of claim 1 wherethe binder is corn starch.
 13. The method of claim 1 where the particlesare one or more of the following particles: stones, polymer beads,biodegradable plastic pellet, fragments of a mineral.
 14. The method ofclaim 1 where the particles that are coated have, in the aggregate, agenerally uniform distribution in particle size and range in size from50 to 0.001 millimeters in diameter.